In many types of welding operations, a wire feeder feeds wire to a welder. The welding wire is normally wound upon coils or reels and is unwound therefrom as wire is being consumed.
One type of wire dispenser is disclosed in U.S. Pat. No. 4,235,624 wherein wire is pulled from a stationary coil. However, a twist or torque is created in the wire and such a twist or torque frequently interferes with the welding operation. Many other types of wire dispensers have also been provided but they are either extremely cumbersome, expensive or difficult to use.
A welding wire dispenser was disclosed in applicant's U.S. Pat. No. 4,456,198 and represented a significant advance in the art. In the device of said patent, the weight of the wire reel causes the reel support to lower into braking engagement. It was found that it is sometimes necessary to move the braking surfaces into contact with one another by means of a spring when the wire on the reel is substantially depleted thereby resulting in less weight. Accordingly, a second patent was granted to applicant on an improvement in a welding wire dispenser and said improvement is disclosed in U.S. Pat. No. 4,465,246.
Although the welding wire dispensers disclosed in applicant's first two patents did represent significant advances in the art, it was found that an improved means for moving the braking surfaces out of frictional engagement with each other was advantageous. The further improved welding wire dispenser of applicant's U.S. Pat. No. 4,508,291 provided an improved means for raising and lowering the coil support and supporting shaft. Applicant has patented yet another improvement of the wire dispenser and the same is disclosed in U.S. Pat. No. 4,602,953.
The welding wire dispensers disclosed in applicant's four patents are each believed to represent a significant advance in the art. The present invention is intended to improve upon applicant's four earlier devices in that the welding wire may be dispensed from the dispenser at a much higher rate of speed than in the earlier devices through the use of an accumulator pulley. The device of the invention also permits wire to be pulled therefrom prior to disengagement of the braking surfaces. Further, the instant invention is more compact and occupies less floor space than some of applicant's earlier devices. A modified device is also described to permit the wire to be dispensed vertically.